1 #include <cstdio>
 2 #include <queue>
 3
 4 #define min(a,b) (a<b?a:b)
 5 #define INF (1<<30)
 6
 7 using namespace std;
 8
 9 const int M(40000+5);
10 const int N(5000+15);
11 int n,m,u,v,ups,dis,s,t,tps;
12
13 int head[N],sumedge;
14 struct Edge
15 {
16     int u,v,wp,wd,nx;
17     Edge(int u=0,int v=0,int nx=0,int wp=0,int wd=0):
18         u(u),v(v),nx(nx),wp(wp),wd(wd){}
19 }edge[M<<1];
20 void ins(int u,int v,int wp,int wd)
21 {
22     edge[++sumedge]=Edge(u,v,head[u],wp,wd);
23     head[u]=sumedge;
24 }
25
26 queue<int>que;
27 int needp[N],needt[N],inq[N];
28 void SPFA()
29 {
30     for(int i=1;i<=n;i++)
31         needp[i]=needt[i]=INF;
32     que.push(s);inq[s]=1;
33     needp[s]=0;needt[s]=0;
34     while(!que.empty())
35     {
36         u=que.front();
37         que.pop();
38         inq[u]=0;
39         for(int i=head[u];i;i=edge[i].nx)
40         {
41             v=edge[i].v;
42             if(needt[v]>needt[u]+edge[i].wd&&needp[u]+edge[i].wp<=tps)
43             {
44                 needt[v]=needt[u]+edge[i].wd;
45                 needp[v]=needp[u]+edge[i].wp;
46                 if(!inq[v])
47                     que.push(v),inq[v]=1;
48             }
49         }
50     }
51 }
52
53 int main()
54 {
55     scanf("%d%d",&n,&m);
56     for(int i=1;i<=m;i++)
57     {
58         scanf("%d%d%d%d",&u,&v,&ups,&dis);
59         ins(u,v,ups,dis);ins(v,u,ups,dis);
60     }
61     scanf("%d%d%d",&s,&t,&tps);
62     SPFA();
63     if(needp[t]==INF) printf("-1");
64     else printf("%d",needt[t]);
65     return 0;
66 }